When to power off a tube amp?

Many recent vintage tube preamps have a slow start cycle built in. It slowly increases the voltage going to the tubes over a 20 to 45 second interval when you turn the preamp on.

Preamps that I know of with this feature include PrimaLuna, c-j and Aesthetix. If your preamp has this feature, I think you should turn it off if you won't be using it for an hour or so. The life of small signal tubes is being used up even when music is not being played through them, although at a slower rate than when music is being played through them.

I am not a tube or electronics expert, so if i am wrong about this, please correct me.

Highroller, whenever this topic comes up there is disagreement. I haven't seen one of these discussions come to an agreement anyway.

Personally, I think the preponderance of the evidence indicates that you should turn your tube preamp off if you are not going to be listening to it within the next two hours.

You want to avoid turning it on and off several times a day also, but to let the tubes burn for hours while not listening is just using them up with no benefit. Turning them on for 10 or 15 minutes of listening doesn't make sense either. If you want to listen for a few minutes use your computer.

If you are using inexpensive current production tubes, leave them on all day and have a spare set handy. Put the new ones in every once in a while and when the new ones sound better than the old ones, leave them in and order another pair.

That's my opinion. I would call the people at Schiit and ask them what they recommend.